* Appliances balance performance with least-cost routing
Technologies are merging to further enhance your ability to manage WAN performance. For example, route optimization appliances are gaining “application awareness” functionality.
This ability to recognize packet types at the application layer is a trait usually associated with traffic-shaping appliances from companies such as AdTran, Allot Communications, Packeteer, Sitara and, most recently, Visual Networks. But the function is now getting bundled into products whose mission in life is to make sure Internet-destined traffic takes the best route in dual- and multi-homed configurations.
For example, the most recent release of software for Proficient Networks’ Network Policy Engine, a route optimization appliance, performs this function. It also measures latency and jitter. And, in cases where the appliance is used with an Internet-based IP VPN, it identifies traffic before it is encapsulated in an IPSec tunnel and becomes unrecognizable, says Proficient’s senior director of marketing, Mathew Lodge.
This allows a performance threshold to be set for that traffic that balances performance with cost when selecting an Internet VPN connection, he says.
The primary function of route optimization appliances – also available from companies such as netVmg, Opnix, Route Science and Sockeye Networks – is to essentially act as a Border Gateway Protocol (BGP) peer with your own Internet access router and the head-end routers of your ISPs, probing and comparing data path performance. If performance is significantly better on an alternate network, the appliance sends path updates that override the existing BGP route, regardless of the number of router hops.
In their initial form, these products did not take application traffic type into account. The application recognition capability enables further control over least-cost routing, explains Lodge. Since enterprises often contract for Internet services based on usage with each ISP, they might want to direct traffic based on cost if performance is virtually the same on both links.
“Consider voice,” Lodge says. “If one link has 50 milliseconds latency and the other has 60, both work equally well.” So you’d likely want to choose the cheaper route. “But if one path has 50 milliseconds latency and the other has 200, that’s a different story.”
